Long-term Safety Evaluation of Spesolimab in Patients with Hidradenitis Suppurativa Following Completion of Initial Spesolimab Treatment Phases

The primary objective of this trial is to evaluate the long-term **safety** of spesolimab in patients with **Hidradenitis Suppurativa (HS)** who have previously completed approximately 8 to 12 months of spesolimab treatment in Part 1 or Part 2 of trial 1368-0098. This assessment is clinically relevant as it aims to determine the sustained safety profile of spesolimab, a therapeutic agent administered as a solution for injection in a pre-filled syringe, for individuals with this chronic inflammatory skin condition. The trial does not specify any secondary objectives.

The clinical trial involves a total of **366 participants** diagnosed with **Hidradenitis Suppurativa (HS)**. The study population includes both male and female subjects, with an age range that encompasses adolescents and adults. Participants were selected based on their completion of approximately 8 to 12 months of spesolimab treatment in a prior trial (1368-0098) without premature discontinuation. The trial includes individuals who are within the defined Residual Effect Period, corresponding to 16 weeks since their last spesolimab administration. The study population is characterized by a diverse range of health statuses, and it includes a vulnerable population. Lifestyle considerations such as diet, physical activity, and habits are not specified. Key inclusion criteria require participants to have provided signed and dated written informed consent in accordance with ICH-GCP and local legislation. Women of childbearing potential must use highly effective methods of birth control. The trial aims to assess the long-term safety of spesolimab in this specific cohort.

The clinical trial is designed to evaluate the long-term safety of **spesolimab** in patients with **Hidradenitis Suppurativa (HS)** who have previously participated in a related study. This trial follows a randomized, double-blind, controlled design, ensuring that neither the participants nor the researchers know who is receiving the active treatment or the placebo, which is matched to spesolimab. The trial is expected to span from May 2024 to April 2030, with participant involvement lasting up to 76 weeks. The primary endpoint is the occurrence of treatment-emergent adverse events (TEAEs), which will be closely monitored throughout the study.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as completion of the prior spesolimab trial without premature discontinuation and adherence to a defined residual effect period. Follow-up visits will be scheduled at regular intervals to assess safety and any adverse events. The end-of-study visit will conclude the participant's involvement, ensuring all necessary data is collected and any ongoing safety concerns are addressed.

Participants are expected to remain in the study for the full duration unless specific conditions necessitate early termination. These conditions include the occurrence of significant adverse events, withdrawal of consent, or non-compliance with study protocols. The trial's methodology and design are structured to provide robust data on the long-term safety profile of spesolimab, contributing valuable insights into its use for treating **Hidradenitis Suppurativa**.

The clinical trial involves the administration of **Spesolimab**, a humanized monoclonal antibody, as the experimental medication. Spesolimab is provided in the form of a **solution for injection in pre-filled syringe**. The active substance, spesolimab, is classified as a protein of other origin. The pharmaceutical form is specifically designed for **subcutaneous use**. The trial does not specify a maximum daily dose or total dose amount, but the maximum treatment period is set at 76 weeks. The administration schedule and dosage frequency are determined by the study protocol, and participant compliance is monitored throughout the trial duration. Spesolimab is identified by the sponsor product code BI 655130 and is manufactured by Boehringer Ingelheim International.

The study also includes a **placebo** that matches the spesolimab formulation. The placebo is used as a comparator treatment to evaluate the efficacy and safety of spesolimab. The placebo is designed to mimic the appearance and administration route of the experimental medication, ensuring blinding in the trial. The placebo does not contain any active substance and is administered according to the same schedule as spesolimab. Participant adherence to the placebo regimen is similarly monitored to maintain the integrity of the trial results.

The efficacy of the clinical trial assessing long-term treatment with **spesolimab** in patients with Hidradenitis Suppurativa (HS) will be evaluated primarily through the occurrence of treatment emergent adverse events (TEAE). This endpoint is designed to monitor the safety profile of **spesolimab** over an extended treatment period. The trial will include participants who have completed approximately 8 to 12 months of **spesolimab** treatment in a previous trial phase, ensuring a comprehensive assessment of long-term safety and tolerability. The data collection will focus on adverse events that arise during the treatment period, providing critical insights into the safety of **spesolimab** for patients with HS. The trial is structured to ensure rigorous monitoring and documentation of any adverse events, contributing to the overall understanding of the therapy's safety profile.